'\" et
.TH PTHREAD_CONDATTR_GETCLOCK "3P" 2017 "IEEE/The Open Group" "POSIX Programmer's Manual"
.\"
.SH PROLOG
This manual page is part of the POSIX Programmer's Manual.
The Linux implementation of this interface may differ (consult
the corresponding Linux manual page for details of Linux behavior),
or the interface may not be implemented on Linux.
.\"
.SH NAME
pthread_condattr_getclock,
pthread_condattr_setclock
\(em get and set the clock selection condition variable attribute
.SH SYNOPSIS
.LP
.nf
#include <pthread.h>
.P
int pthread_condattr_getclock(const pthread_condattr_t *restrict \fIattr\fP,
    clockid_t *restrict \fIclock_id\fP);
int pthread_condattr_setclock(pthread_condattr_t *\fIattr\fP,
    clockid_t \fIclock_id\fP);
.fi
.SH DESCRIPTION
The
\fIpthread_condattr_getclock\fR()
function shall obtain the value of the
.IR clock
attribute from the attributes object referenced by
.IR attr .
.P
The
\fIpthread_condattr_setclock\fR()
function shall set the
.IR clock
attribute in an initialized attributes object referenced by
.IR attr .
If
\fIpthread_condattr_setclock\fR()
is called with a
.IR clock_id
argument that refers to a CPU-time clock, the call shall fail.
.P
The
.IR clock
attribute is the clock ID of the clock that shall be used to
measure the timeout service of
\fIpthread_cond_timedwait\fR().
The default value of the
.IR clock
attribute shall refer to the system clock.
.P
The behavior is undefined if the value specified by the
.IR attr
argument to
\fIpthread_condattr_getclock\fR()
or
\fIpthread_condattr_setclock\fR()
does not refer to an initialized condition variable attributes object.
.SH "RETURN VALUE"
If successful, the
\fIpthread_condattr_getclock\fR()
function shall return zero and store the value of the clock attribute
of
.IR attr
into the object referenced by the
.IR clock_id
argument. Otherwise, an error number shall be returned to indicate the
error.
.P
If successful, the
\fIpthread_condattr_setclock\fR()
function shall return zero; otherwise, an error number shall be
returned to indicate the error.
.SH ERRORS
The
\fIpthread_condattr_setclock\fR()
function may fail if:
.TP
.BR EINVAL
The value specified by
.IR clock_id
does not refer to a known clock, or is a CPU-time clock.
.P
These functions shall not return an error code of
.BR [EINTR] .
.LP
.IR "The following sections are informative."
.SH EXAMPLES
None.
.SH "APPLICATION USAGE"
None.
.SH RATIONALE
If an implementation detects that the value specified by the
.IR attr
argument to
\fIpthread_condattr_getclock\fR()
or
\fIpthread_condattr_setclock\fR()
does not refer to an initialized condition variable attributes object,
it is recommended that the function should fail and report an
.BR [EINVAL] 
error.
.SH "FUTURE DIRECTIONS"
None.
.SH "SEE ALSO"
.ad l
.IR "\fIpthread_cond_destroy\fR\^(\|)",
.IR "\fIpthread_cond_timedwait\fR\^(\|)",
.IR "\fIpthread_condattr_destroy\fR\^(\|)",
.IR "\fIpthread_condattr_getpshared\fR\^(\|)",
.IR "\fIpthread_create\fR\^(\|)",
.IR "\fIpthread_mutex_destroy\fR\^(\|)"
.ad b
.P
The Base Definitions volume of POSIX.1\(hy2017,
.IR "\fB<pthread.h>\fP"
.\"
.SH COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1-2017, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 7, 2018 Edition,
Copyright (C) 2018 by the Institute of
Electrical and Electronics Engineers, Inc and The Open Group.
In the event of any discrepancy between this version and the original IEEE and
The Open Group Standard, the original IEEE and The Open Group Standard
is the referee document. The original Standard can be obtained online at
http://www.opengroup.org/unix/online.html .
.PP
Any typographical or formatting errors that appear
in this page are most likely
to have been introduced during the conversion of the source files to
man page format. To report such errors, see
https://www.kernel.org/doc/man-pages/reporting_bugs.html .
